Suggest Treatment For Blisters On Chest

I am a Female, I am 19 years old and i have a spot on my chest that resembles a blister when it has no fluid in it and s healing except there was never a blister there and the skin is peeling before i started to pick at it it was colorless but now it is slightly pink around the edges but it does not hurt it has been here for a day or two. It just bothers me because it's not something i am familiar with or have had any luck finding any clues about online. I do not have the money to see a doctor so please try to be as helpful as possible. I know that I have ulcers (inside not out) and tend to have a poor immune system. Help?